This invention relates to apparatus for use with an intermittently operable slide projector or other still picture projector and with an audio tape recorder-reproducer to facilitate changing of the picture at desired times when a tape is being played.
Apparatus of this general type is known and normally comprises means for recording on magnetic tape a suitable picture change signal either on the same channel or on a separate channel from that used for the audio recording. During playback of the tape, the change signal is detected and processed for producing a signal that is used to effect a slide changing operation by the projector. A nonexclusive listing of prior patents which show apparatus of this type includes U.S. Pat. Nos. 2,811,588, 3,276,315, 3,342,103, 3,402,966 and 3,612,675.